我已经提交了googlebatchtranslation并获得了operationid（projects//locations/us-central1/operations/）。
现在我想通过池来检查此操作的状态。这里我用了下面的依赖项

<dependency>
  <groupId>com.google.api</groupId>
  <artifactId>gax-grpc</artifactId>
  <version>1.58.2</version>
</dependency>
<dependency>
  <groupId>com.google.api</groupId>
  <artifactId>gax</artifactId>
  <version>1.58.2</version>
</dependency>

在java类中添加了以下代码：

GoogleCredentials credentials = GoogleCredentials
                                .fromStream(new ByteArrayInputStream(serviceKey.getBytes()))
                                                                                   .createScoped(Lists.newArrayList("https://clicktime.symantec.com/3TWFMHceuuMgwf8KebwWinm7Vc?u=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fcloud-platform%2522%29%29%3B
OperationsSettings operationsSettings =                OperationsSettings.newBuilder().setCredentialsProvider(FixedCredentialsProvider.create(credentials)).build();

OperationsClient operationsClient = OperationsClient.create(operationsSettings);

但是在这里，我在尝试创建operationsclient时遇到了nullpointerexception

at com.google.longrunning.stub.OperationsStubSettings.createStub(OperationsStubSettings.java:107)
                at com.google.longrunning.OperationsClient.<init>(OperationsClient.java:143)
                at com.google.longrunning.OperationsClient.create(OperationsClient.java:125)

进一步调查发现，创建的operationssettings将transportchannelprovider设置为null。
请指导我，我在创建operationsettings/operationclient时是否遗漏了什么？在java中查找google长时间运行操作状态的最佳方法是什么。
谢谢，兰Git·库马尔